Hydraulic jack for removing rock drill steels



July 20, 1937. c. E. GoNsER ET A1.

HYDRAULIC JACK FOR REMOVING ROCK DRILL STEELS Filed April 2, 1935 Patented July 20, 1937 UNITED STATES PATENT oFFicE HYDRAULIC JACK FOR REMOVING ROCK DRILL STEELS Charles E. Gonser and Cecil D. Hingley, Denver, Colo.

Application April 2, 1935, Serial. No. 14,200

1 Claim.

This invention relates to a jack for removing stuck rock drills from the drill holes and has for its principal object the provision of a hydraulic Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and eiilciency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawing which yforms ay part hereof. Like numerals referto like parts in all views of the drawing and throughout the description.

`In the draWingI- Fig. 1 is a plan view of the improved drill steel pulling jack.

Fig. 2 is a vertical section therethrough, taken on the line 2 2, Fig. l.

Fig. 3 is a similar view illustrating the jack in the partially raised position. l

The invention comprises a base I0, upwardly from which, three concentric cylinders extend. The cylinders consist of an inner cylinder II, which preferably extend entirely through the base IIJ, and an outer cylinder I2, surrounded by a reservoir cylinder 3.

All of the cylinders are liquid tight to the base I and the cylinders l2 and I3 are closed to each other at the top and spaced apart to form a fluid reservoir. The cylinders II and I2 are spaced apart to form an annular pressure chamber into which a cylindrical jack plunger I4 projects. The plunger I4 terminates in a head I5 at its top and in a suitable packing washer I6 at its bottom.. A conical hole I1 is formed concentrically through the head I for receiving split conical gripping dogs I8. Channels in the inner faces of the dogs provide a passage for the drill steel. The grooves are formed with ratchetlike gripping teeth 30.

A fluid pressure pump I9 is mounted on the base I0 and provided with a suitable operating handle 2li. The handle 20 reciprocates a pump Isteel.

piston 2| in the pump I9. A feed passage 22 extends from the pump to the fluid reservoir between the cylinders I2 and I 3. The passage 22 is controlled by means of a suitable check valve 23. A pressure passage 24 leads from the pump 2l to the pressure chamber between the f cylinders II and I2. The pressure passage is controlled by means of a suitable check valve 25.

A by-pass passage 26 communicates between the two passages 22 and 24, and is controlled by means of a suitable needle valve 21.

In Fig. 3, a typical rock drill steel is indicated at 28. Let us assume that this steel is stuck in the drill/hole of a rock surface 29 so that it cannot be removed by ordinary methods. To apply the invention thereto, it is only necessary to set the entire jack` over the projecting drill` steel 28, with the steel extending upwardly through and protruding from the inner cylinder II.l The two split dogs I8 are then dropped into the conical opening I1 in the head I5 at each side of the steel.

The pump 2l is now operated to force uid from the reservoir into'the pressure chamber.

' This fluid raises the jack plunger I4, causing the dogs I8 to wedge `themselves between the conical i sides ofthe opening Il and the drill steel so as to force the teeth 30 into the latter. Further upward movement of the plunger withdraws the steel from the drillv hole in the rock 29.

If the steel is not loosened after being elevated the full heighth of the jack, the needle valve 21 is opened. This allows the fluid to iiow from the pressure chamber through the bypass 26 and back to the reservoir, and allowsthe head I5 to lower by gravity. The i'lrst lowering movement of the head acts to release the dogs I8 from the drill steel owing to the conical shape of the hole I'I so that the dogs will slide downwardly along the The pump is now actuated to cause the dogs to again grip the steel and elevate the latter. This process, oi course, can be continued until the entire steelhas been withdrawn from the hole.

While a, specific form of the improvement has been described and illustrated herein, itis desired to be understood that the same may be varied, within the scope of the appended claim, Without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent istr A hydraulic jack for withdrawing rock drill steel comprising in combination: a base; a. ilrst cylinder extending through said base and pro- Jectingabove the top thereof a second cylinder concentrically surrounding said ilrst cylinder and extending upwardly from the top of said base; a third cylinder concentrlcally surrounding the other cylinders and extending upwardly from the top oi' said base; means for sealing the upper extremities of said second and third cylinders together; a cylindrical plunger slidably mounted between said nrst and second cylinders; a head on said plunger having an axial opening in alignment with the hollow interior of said ilrst cylinder; clamping members in said opening; a pump mounted onsaid base; a conduit extending from said pump to the space between said ilrst and second cylinders; a second conduit from the space between said second and third cylinders to said pump; a bypass passage communicating between said two conduits; and a valve for controlling said bypass passage.

CHARLES E. GONSER. CECIL DfHINGLEY. 

